a. Field of the Invention
This invention relates to a gas blast circuit breaker having a movable contact, a mating contact and a nozzle aperture through which the movable contact can travel. More particularly, the nozzle aperture is disposed in a wall dividing the switching chamber which generates a quenching gas flow initiated by the arc.
b. Description of the Prior Art
A gas blast circuit breaker of this type is described in the German Offenlegungsschrift No. 23 49 246. In it, the quenching gas flow is set in motion by an auxiliary arc drawn in the course of the interrupting action which blasts the arc drawn between the movable contact and the mating contact. In this structure the quenching gas flow is dependent on the current to be interrupted or the current flowing in the arc.
In some cases it is desirable to set in motion an additional flow of quenching gas which is independent of the current as soon as an "off" command is given.
It is an object of this invention to provide a gas blast circuit breaker of this type, in which, in addition to the generation of a quenching gas flow dependent on the current, a quenching gas flow, independent of the current, is supplied.